1. Field of the Invention
The invention relates to automated railroad operation generally, and more particularly to a system and method for automatically activating a train warning device at a location for which a warning is required or desirable, such as a grade crossing.
2. Discussion of the Background
More than 4,000 collisions between trains and vehicles occur at public and private highway-rail grade crossings every year, resulting in more than 400 deaths annually. Approximately 50% of these accidents occur at grade crossings with active warning devices such as bells, flashing lights, and/or gates. Recently, some state and local governments enacted legislation prohibiting the use of horns at certain location and/or times. The Federal Railroad Administration (FRA) has studied the effect of this legislation. As a result of this study, the FRA determined that the sounding of train horns significantly reduces accidents at grade crossings. 65 Federal Register 2230 et seq.
As a result, the FRA promulgated several regulations, including 49 C.F.R. xc2xa7222.21, which regulates how and when horns are to be sounded. Under 49 C.F.R. xc2xa7222.21, in the absence of a state regulation, a horn must be sounded starting at a position no greater than xc2xc mile away from the grade crossing. Furthermore, the railroad must place a whistle board (a wayside sign telling the conductor to begin sounding a horn) at a location such that a train traveling at the maximum speed will begin sounding its horn 20 seconds before the crossing, or the railroad must ensure by other methods that the horn is sounded no less than 20 seconds, but not more than 24 seconds, before the locomotive enters the grade crossing. If a state regulation is currently in place, the rule does not disturb the state regulation until a change in the maximum allowable speed is made, at which time the requirement of 49 C.F.R. xc2xa7222.21 become effective. It will be readily apparent from the above discussion that precisely determining when to begin sounding a train horn is not a trivial task.
Even if a device such as a whistle board is present to inform an engineer as to the precise location to begin sounding a train horn, engineers sometimes make mistakes and don""t begin sounding the horn at the right time. In many court cases brought against the railroad operator relating to grade crossing accidents, the engineer is accused of causing the accident by failing to blow the horn correctly.
What is needed is a method and system that will automatically activate a horn in a prescribed manner at an appropriate place and time.
The present invention meets the aforementioned need to a great extent by providing a method and system for automatically activating a train warning device that uses a positioning system such as a global positioning system (GPS) receiver an inertial navigation system (INS) to determine the train""s position. The system further includes a database containing locations of grade crossings and other locations at which a train is required to activate a warning device, as well as what regulations govern activation of the warning device at such locations.